There are one or two things here worth noting, although the general concept of underlying cultural affinities between Africa and Latin America, alluded to in the title, doesn’t really come to much. And as usual, Saatchi’s selection has its own mysterious agenda, unilluminated by theme. As I see it, he is just patrolling the periphery of the global or One World art market, impatient with more central trends. Still, no-one can accuse him of being predictable or doctrinaire. Regrettably, curator Gabriela Salgado's (for part one) and Osei Bonsu’s (part two) catalogue notes are a step in that direction, with their plodding post-colonial agenda. It would have been so much better if the catalogue had just contained a brief Q&A with the man – as his little books have done – in which a few details as to when and where he started collecting work from these regions, any travels or acquaintances this involved, whether he was guided or alerted by others at various points. One assumes the selection and hang are his work and it is spacious and perfectly judged, as most of his Chelsea shows have been, and really this is enough. The catalogue and interpretation remain essentially formalities Saatchi feels obliged to provide, but rarely, if ever do the shows justice.

I’d heard talk of the rise in the market for African art even before Part One of Pangaea last year, as part of art fair online gossip, but hadn’t really followed it. When I think of contemporary African art I still think of artists like Cherie Samba (80s), Odili Donald Odita (90s) or El Anatsui (00s) this, while laying South African examples like Dumas or Kentridge to one side, since they enjoy other cultural advantages. Obviously there is a steady trickle of African artists gaining recognition in Europe or America, often involving migration. But is it worth grouping them under something as vast and amorphous as ‘African’? The same goes for Latin American artists, of course. And what of local art markets in the respective continents? The state of patronage for most of these artists in their home countries remains obscure and vaguely troubling. The film theorist Peter Wollen once coined the term ‘para-tourism’ for precisely this kind of marketing. That now seems to be the lot of the global artist, irrespective of origin.

Anyway, the current show is Part Two, and slightly better by my reckoning. It doesn’t have Gómezbarros’ giant ants made from casts of skulls or Lerma and Madera’s enormous bust of Emanuel Augustus assembled from painted bags of paper – real attention grabbers - and current local star Oscar Murillo doesn’t earn an encore after being comprehensively out-pointed by Ibrahim Mahama (who is back with smaller works, still mainly sacking) in the monster abject/distress stakes. That sort of thing is more or less what I expected, given global trends. That, and the Expressionist trope that segues with graffiti represented here by Aboudia, recalling (as most critics note) Jean-Michel Basquiat in a particularly fraught mood. That seems almost a cliché lately, but given Aboudia’s dire circumstances, understandable. The surprise is that Saatchi picks up on a number of painters with a quieter, more discreet vision.

For me the standouts are Armand Boua, and Dawit Abebe, followed by Diego Mendoza Imbachi, Eddy Ilunga Kamuanga, Eduardo Berliner and Alida Cervantes. If I had to link them somehow it would be their avoidance of a post-modern or post-colonial concern with academic and historical styles, with pastiche or parody. They seem to have moved past that. Their take is more idiosyncratic or personal, more nuanced or ambiguous. Their work does not look especially African or Latin American; could as easily come from other forgotten corners of the globe. But equally, it does not look like it could have come from any of the main Western centres. They seem to be artists, equally sophisticated, mature and informed, that have somehow steered clear of current dogma and fads. Perhaps it takes a periphery to enable this, or at least to enable its perception or reception. The work still deals in political and social issues, but in ways less obvious and simplistic; that skew rather than skewer the topic. I imagine something like this is what attracted Saatchi. There is also a welcome lack of pretension, a confidence in more personal idioms that is some distance from predictable identity politics or correctness. And that may be why Bonsu’s notes on these artists seem particularly clumsy.

The downside is that such work may appear banal or conservative by the standards of the centre. Therein lies the struggle for invention or change. The assumption that artistic change is accompanied by outrage or scandal is a half truth at best. As often, originality is confused with incompetence or mediocrity. It’s not that such work defies available categories, but that initially it is dealt with by inappropriate ones. We often don’t see what all the fuss is about, until we have had time to reflect upon our categories and accept some adjustment. Contrary to myth, it takes time to make important change. Will anyone go along with Saatchi’s choices here? That remains to be seen. Both shows range across a number of possibilities and he is not irrevocably committed to any of his collections. Three of the artists, Murillo, Mahama and Mikhael Subotzky (a South African photographer) are included in this year’s Venice Biennale, but predictably, they are the most conventional of Saatchi’s selections.

Saatchi’s reputation also has its pros and cons. While the gallery boasts impressive attendances and cultivates a measure of populism, it is also seen as no more than a marketing tool by public galleries and their roving body of curators. This happy clique supposedly maintains critical values independent of sales hype. But the distinction in practice is illusory. Saatchi is hardly the unthinking creature of indulgence anymore than say, Hans Ulrich Obrist or Okwui Enwezor are models of stern analytical reflection. One follows criticism discreetly, attending to the market; the other follows the market at a safe distance, insisting on criticism. Discretion is the better part of fervour, really. As noted, there is some crossover in preferred artists, and neither has a monopoly on the public’s sympathy. Significantly, the show has so far drawn reviews (as opposed to mere notices or regurgitated press releases) from just Brian Sewell for The Evening Standard and Zoe Pilger for The Independent. The usual Fleet Street suspects are conspicuous by their absence. Sewell, the Lady Bracknell of art criticism, takes the show (Part One at least) as confirmation of an accelerating pace in the globalised art world, as if the work were now interchangeable with that of centres like London or New York. While this is partly true (hence the inclusion of the London-based Murillo rhymes perfectly with someone like Mahama) it misses vital differences.

A Post Colonialist might argue that changes are initiated at the periphery, from neglected or obscure zones of an empire and that these steadily feed back to the centre as a kind of perversion or mutation of tradition and tacitly confirm diffusion and decline. When an empire gets big enough, it falls apart. That much seems certain and applies equally to our one big global art world. It may take some time for the feedback to become part of the message, but with shows like this we see (and so sew) the seeds.